It is not an ownership issue it is an integrity issue. When quotes carefully selected to corroborate a premise while ignoring writings by the very same authors that substantiate Catholic doctrines it is an exercise in sophistry. Not just Catholics, but anyone interested in truth objects.
If you step back from the passion of the argument and look at arguments based upon the balance of their substantiation and the use of euphemisms you will begin to recognize sophistry. That is a valuable skill set when living in a society that is highly manipulated by advertisers and political machinery.
Peace be with you
If it is not an issue of "ownership", then why the disparagement of any non-Catholic who uses stated beliefs of said persons? It is the height of sophistry to object to the use of thoughts and ideas of Christians from centuries past when those writings are shown to prove the contention being made. Just as the link I gave demonstrated, the Reformers had the backing of Holy Scripture as well as those early theologians to know what actually WAS orthodoxy and it is how they knew that the Roman Catholic Church at that time had strayed from that orthodoxy. A case in point was the concept of Purgatory and the use of money to buy a loved ones way out of that state, called Indulgences. Yes, we've all heard the rationalizations that the "Church" did not "officially" condone that activity, but it is undeniable that no one did much to discourage it from happening especially since the vast amounts of money collected helped to build the magnificent St. Peter's Basilica. And it is equally undeniable that the Church put a stop to that activity after the fact.
Of course, that is not the only doctrinal disagreement and it was quite telling about the state of pride and feared loss of control that the Catholic Church doubled-down and issued anathemas over doctrinal issues that they had at one time allowed, i.e.; justification by faith.
Think about this...if there were no questions at all about what are and are not the orthodox tenets of the Christian faith, then why was the Reformation started? Why had there been a schism from the Orthodox in the East five hundred years earlier that, to this day, is not yet fully mended? The Orthodox rejected the dogmas of the Primacy of the Pope of Rome along with many of the Marian dogmas, they disagreed over the wording of the Filioque and other doctrinal points. It was the stubbornness of the hierarchy in Rome that refused to reconsider their changed dogmas from what had always and everywhere been believed and that same stubbornness had not ebbed five hundred years later when the Reformers brought the same complaints.
These brave men and women tried to restore the Church back to what was the true Gospel and they were repelled not because the Church was right, but because they had too much to lose by admitting failure to uphold the truth of Christianity. They could not reform what they would not admit needed to be reformed and it was that pride and stubborn hold on power that caused the second split. The Reformers did not leave the Church, the Church left them. I, as well as millions, left the Roman Catholic Church when we saw what the Reformers also saw. The Catholic Church had ceased to BE catholic and left the most major doctrine that brought about the very salvation that it claimed to herald - that man is saved by faith apart from works because of the grace of God.
So please, spare me the lectures about "integrity". Integrity is speaking up for the truth even if it means admitting error and then making the needed changes to remain in truth. That truth is God's word and it is not an impossible source to understand. God gives us His Spirit to enable us TO understand His truth and that is what we must rely upon.